我正在运行一个简单的hello world程序，用C语言在mpi上编写，我遇到的问题是，我似乎不能为这个简单的程序执行10个进程。

#include <stdio.h>
#include "mpi.h"

int main(int argc, char *argv[])
{
    int rank; //rank of the process
    int size; //number of processes

    MPI_Init(&argc,&argv); //inititate MPI environment
    MPI_Comm_rank(MPI_COMM_WORLD,&rank);
    MPI_Comm_size(MPI_COMM_WORLD,&size);

    printf("Hello world from process %d of %d\n",rank,size);
    MPI_Finalize();
    return 0;
}

我在终端上通过以下方式运行它：

mpicc -o hello helloworld.c
mpirun --oversubscribe -np 10 hello

输出量：

Hello world from process 0 of 10
Hello world from process 2 of 10
Hello world from process 3 of 10
Hello world from process 9 of 10
Hello world from process 7 of 10
Hello world from process 1 of 10
Hello world from process 6 of 10
Hello world from process 5 of 10
Hello world from process 4 of 10
Hello world from process 8 of 10
----------------------------------------------------------------------- 
---
A system call failed during shared memory initialization that should
not have.  It is likely that your MPI job will now either abort or
experience performance degradation.

我意识到我的双核mac上的最大订阅量是5，这不会产生如上所述的警告，但任何超过这一点的东西都会给我错误，我不知道为什么。
希望能在这方面得到一些帮助。如果是这样的话，我该如何重新安装打开的mpi？